<!DOCTYPE html>
<html class=reftest-wait>
<meta charset="utf-8">
<title>CSS Anchor Positioning Test: position-visibility: anchors-visible</title>
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/7758">
<link rel="match" href="position-visibility-anchors-visible-chained-004-ref.html">
<script src="/common/reftest-wait.js"></script>
<script src="/common/rendering-utils.js"></script>
<style>
  #scroll-container {
    overflow: hidden scroll;
    width: 300px;
    height: 100px;
  }

  #anchor1 {
    anchor-name: --a1;
    width: 100px;
    height: 100px;
    background: orange;
  }

  #anchor2 {
    anchor-name: --a2;
    width: 100px;
    height: 50px;
    background: blue;
  }

  .spacer {
    height: 100px;
  }

  .anchored {
    position-visibility: anchors-visible;
    position-area: bottom;
    width: 100px;
    height: 50px;
    background: green;
    position: absolute;
    top: 0;
    left: 0;
  }

  #chained {
    position-anchor: --a1;
  }

  #target {
    position-anchor: --a2;
  }
</style>

<div id="scroll-container">
  <div id="anchor1">anchor1</div>
  <div class="spacer"></div>
  <div id="chained" class="anchored">
    <div id="anchor2">chained</div>
  </div>
  <div id="target" class="anchored">target</div>
</div>

<script>
  // #target should be initially visible because it is anchored to #anchor2
  // which is chained to #anchor1 and both anchors are visible.
  waitForAtLeastOneFrame().then(() => {
    // Scroll #anchor out of view.
    const scroller = document.getElementById('scroll-container');
    scroller.scrollTop = 100;
    // #target1 should now be invisible.

    waitForAtLeastOneFrame().then(() => {
      // Scroll #anchor back into view.
      scroller.scrollTop = 0;

      // #target should now be visible again.
      takeScreenshot();
    });
  });
</script>
